Extract text from a PDF,free, in your browser

No. The text is pulled out in your browser and the .txt file is built there too. Nothing is uploaded, which matters for contracts, statements and anything else confidential.

Your PDF is almost certainly a scan. A scanned page is a photograph of a document, so there is no text inside the file to extract. Run it through the OCR tool first to add a text layer, then convert it here.

No, and that is deliberate. You get the reading order as plain text, not columns, tables and positioning. If you need the layout preserved, convert to Word instead.

They mark where each page began, so you can trace a line of text back to its page in the original. Turn them off if you want one continuous block of text, for example when feeding the output into another tool.

Not while it is locked. Remove the password with the unlock tool first, then extract the text.

No fixed limit. Long PDFs take longer because every page is read in turn, and the tool shows which page it is on as it works.